Thanks for the info so far. I have my oil change receipts, most show mileage since oil change in the 4000-4500 range, a couple in the mid-3000 range, and just one that was close to 7000 a couple years ago. I checked the dates and figured out that was the summer my grandfather died, and I made several 2-hour interstate trips to my parents’ town, so the mileage was up but the time interval was similar to usual. I am taking the car in to the dealer to investigate further.